Ultrasound contrast media

What are Ultrasound contrast media?

Ultrasound contrast media is used to increase the contrast of the sonogram image by enhancing the reflection of the ultrasound waves. This occurs due to the difference in the ability of the contrast media and the soft tissue to reflect the ultrasound wave.

The ultrasound contrast media can be gas-filled microbubbles that are used to image blood flow or perfusion, or can be site-targeted microbubbles that can attach to specific markers.

Microbubbles are currently the only clinically approved ultrasound contrast agent. One of the strengths of these bubbles is that they remain intravascular due to their size, allowing for diagnostic measurements that would be otherwise difficult with diffusible tracers.

Here are the four types of contrast media and relative contrast compounds:

Oral Contrast Media.
Intravenous Contrast Media.
Rectal Contrast Media.
Microbubble Contrast Media.

The contrast agent microbubbles reached by an ultrasound beam powerful enough explode producing a strong and very short backscatter echo which is read by the unit as a Doppler signal and results in a color pixel where the individual microbubble exploded.